1. Field of the Invention
This invention relates to self steering systems for sailing craft and more particularly to such a system which employs a rotatably and pendulously supported oar member which is suspended in the water stream behind the craft which is used to control the sailing craft in response to a device such as a wind vane which senses and provides an output signal in accordance with changes in boat heading from a preset heading relative to the wind direction.
2. Descriptions of the Related Art
Self steering systems for sailboats are described in my prior U.S. Pat. No. 3,983,831 issued Oct. 5, 1976; U.S. Pat. No. 4,327,657 issued May 4, 1982; U.S. Pat. No. 4,766,833 issued August, 1988; and U.S. Pat. No. 5,309,858 issued May 10, 1994. Each of the systems described in the above patents employs a different implementation, which makes for some advantage in operation or fabrication. The present invention is most closely related to the device of U.S. Pat. No. 5,309,858 and will therefore be compared in its implementation to that of this patent.
The system of U.S. Pat. No. 5,309,858 employs a pendulum body rotating on a fixed pendulum shaft. The pendulum shaft is attached to a universal bracket, which is fixedly attached to the transom of the sailboat. The system has a major upright section, which includes a base and a tubular wind vane support extending upwardly from the base. This wind vane support is secured to the pendulum shaft and positioned aft of the pendulum body. An output “pull-pull” line attachment shoulder or rocker is positioned on the top of the pendulum body, above the pendulum shaft. Pull-pull output lines run to a set of blocks positioned on opposite sides of the attachment shoulder.
It has been found that the location of the pull-pull lines in prior art systems obstructs swim ladders and “walk-thru” features of the boat. In addition, it has been found to be difficult to correctly position the “pull-pull” line side blocks with double ended boat geometry, a strongly curved boat transom or with off center mountings of the main elements of the system.
Additionally, the pendulum shaft is subject to damage from high accidental mechanical loads from the upright wind vane support, requiring an extra large diameter for the shaft.
A still further disadvantage of this prior art system is that it employs a complex universal bracket which is capable of holding the extra-large pendulum shaft and adapting to a wide range of different transom angles.